Field of the invention
[0001] This invention relates to peripheral devices that can be connected to a computer,
and more specifically to powering and/or charging such peripheral devices.
Background of the invention
[0002] Widespread peripheral devices that can be connected to a computer, such as personal
data assistants, cell phones and printers, are either powered by the computer to which
they are connected, or are self-powered by their own power supply. Some peripheral
devices can be powered in both manners.
[0003] In addition to connecting to a computer for powering, a peripheral device having
its own battery pack may be connected to a computer for charging.
[0004] For example, a PDA can be connected to a computer to draw power therefrom. Additionally,
the PDA can have its own battery pack as a power supply. If the battery pack needs
charging, the PDA can be connected to the computer for this purpose.
[0005] A convenient method to power or charge a PDA in a mobile setting involves the use
of a laptop computer. If the PDA is running low on batteries in the field, the PDA
can be connected to a battery-operated laptop computer for charging and/or powering.
If one power outlet is available, the computer can be plugged into the one outlet
and the PDA can be connected to the computer to charge and/or power the PDA.
[0006] To make such a connection between a computer and a peripheral device, it is necessary
to have installed in both the computer and the peripheral device appropriate software,
known as a device driver, to establish and control the connection.
[0007] Device drivers can be categorized according to the communication standard to which
they adhere. One category of device drivers adheres to the standard known as universal
serial bus, better known by its acronym USB. Device drivers that are USB compliant
are convenient because many PC's come with two USB ports. Special USB devices, called
USB hubs, have additional ports that allows multiple peripheral devices to be daisy
chained, which is possible because USB permits many peripheral device connections
at one time.
[0008] Another convenient USB feature is that it distributes electrical power to many peripherals.
USB lets the PC automatically sense the power that is required and deliver it to the
device. USB "hot-swapping" obviates the need to shut down and restart the PC to attach
or remove a peripheral device: the PC automatically detects the peripheral and configures
the necessary software. This feature is especially useful for users of multi-player
games, as well laptop PC users who want to share peripheral devices.
[0009] As convenient as USB is, one major drawback has been mentioned above, namely for
a USB connection to be made between a PC and a peripheral device, it is necessary
that a USB device driver be installed in the PC. This necessity is inconvenient for
a number of reasons. First, time and expenses are required to write the device driver
in the first place. Next, the driver has to typically be certified by undergoing several
tests. Finally, the specific driver required may not be that widespread, so an attempt
to connect to a foreign PC may fail if the PC does not have the driver.
[0010] As an example, a user of a USB handheld device cannot charge the device from a Windows
™ based PC unless the proper Windows USB drivers have been installed. This limits the
ability of the user to power and/or charge a device with a dead or low battery in
the field on a PC that does not have the requisite handheld device driver installed.
Moreover, as mentioned above, even for such relatively simple operations as charging
or powering, the manufacturer of the peripheral device is required to develop and
certify a USB driver, which is an involved and costly process.
Summary of the invention
[0011] The present invention addresses the aforementioned problem of requiring a specific
driver on a computer to charge or power a peripheral device by leveraging the ubiquitous
availability of USB hub drivers on Windows
™-based PC's.
[0012] In particular, the invention exploits the fact that pre-packaged, generic USB hub
drivers are shipped with every version of the Windows
™ operating system (after and including Win98
™). Even though the peripheral device is not a hub, the device can present itself as
such to avail itself of these drivers. For example, the peripheral device can present
itself as a simple USB hub, such as a zero-port hub, or possibly a one-port hub, depending
on what certification requires as the definition of a hub. These hubs can then utilize
the existing, pre-packaged drivers. In this manner, the peripheral device can draw
power from any Windows
™-based PC, without the need of using specially written and certified drivers.
[0013] Example applications include recharging of batteries, or even fully-powering a device.
Any electronic device can be powered in this way. Furthermore, the present invention
can eliminate the need to supply an AC adapter with equipment that can be powered
according to the principles of the invention, reducing the overall cost of the device.
[0014] Described herein is system and method for charging or powering a peripheral device.
The system includes a connector for connecting the device to the computer, and a software
module in the peripheral device that enables the peripheral device to be charged or
powered by a computer.
[0015] The software module includes a first signal module for sending a first signal to
the computer that identifies the peripheral device as a hub, regardless of its true
identity. A second signal module sends a second signal to the computer that indicates
that one more peripheral device is connected to the peripheral device identified as
a hub than is actually connected to this device. Thus, in the simplest case where
only one peripheral device is connected to the computer for powering, the second signal
module indicates to the computer that one peripheral device is connected to the hub;
in reality, the peripheral device is neither a hub nor a device that is connected
to another peripheral device. However, by representing itself as such to the computer,
the peripheral device can a) avail itself of the services of the hub driver in the
computer, and b) draw appropriate power and/or charge from the computer.
[0016] The system further includes a power-charge receptor, which includes the necessary
hardware, such as resistors, capacitors, etc., for powering or charging the peripheral
device identified as a hub from the computer.
Brief description of the drawings
[0017] For a better understanding of the present invention and to show more clearly how
it may be carried into effect, reference will now be made, by way of example, to the
accompanying drawings, in which:
Figure 1 shows a system for powering and/or charging a peripheral device, in accordance
with the principles of the present invention;
Figure 2 shows another system for powering and/or charging two linked peripheral devices,
in accordance with the principles of the present invention; and
Figure 3 shows a flowchart for powering and/or charging a peripheral device, in accordance
with the principles of the present invention.
Detailed description of the invention
[0018] Figure 1 shows a system 10 for charging or powering a peripheral device 12 by connecting
the peripheral device 12 to a computer 14. For example, the peripheral device 12 can
include a personal digital assistant (PDA), a telephone, a digital camera, a modem,
a keyboard, a mouse, a joystick, a CD-ROM drive, a tape drive, a floppy drive, a digital
scanner, a printer, a data glove or a digitizer.
[0019] The system 10 includes a connector 16, and a software module 18 residing in the peripheral
device 12. The software module 18 includes a first signal module 20 and a second signal
module 22. The system 10 further includes a power-charge receptor 24 disposed in the
peripheral device 12.
[0020] The software module 18 includes software and/or hardware that enables the peripheral
device 12 to be charged or powered by the computer 14. As discussed in more detail
below, the software module 18 includes the first signal module 20 for sending a first
signal to the computer 14 that identifies the peripheral device 12 as a hub. The software
module 18 also includes the second signal module for sending a second signal to the
computer 14 that indicates that a peripheral device is connected to the hub. The signals
can be sent via the connector 16, which connects the peripheral device 12 to the computer
14.
[0021] The power-charge receptor 24 in the peripheral device 12 is the electrical hardware
that is needed to power or charge the peripheral device 12 from the computer 14 in
response to the first and second signals. The power-charge device 24 can include circuit
elements, such as resistors and capacitors, to power or charge the peripheral device
12.
[0022] In a preferred embodiment, the peripheral device is USB compliant and is powered
and/or charged with the computer 14, such as a personal computer (PC). The PC may
be running the Windows
™ operating system, which typically includes a pre-packaged, generic USB hub driver.
For example, Windows 98/98SE
™ mostly supports USB, and Windows 2K/XP/2003
™ fully supports USB support.
[0023] As used herein, a hub is a device that principally serves to connect several devices
together, and to optionally provide power to them. For example, a hub may be used
to connect several computers and several peripheral devices together. A bus-powered
hub derives power from the bus of the computer(s) to which it is connected and, in
turn, provides power to other devices to which it is connected. Other hubs are self-powered.
[0024] The present invention exploits the fact that many personal computers have pre-packaged
USB hub drivers as part of their operating systems. For example, current versions
of the Windows
™ operating system come pre-packaged with a USB hub driver. By representing itself
as a hub, instead of representing itself as a PDA, for instance, the hub driver can
serve to provide charge or power to the peripheral device 12.
[0025] By installing the software module 18 in the peripheral device, there is no need for
the computer 14 to have a driver that is specific to the peripheral device. Instead,
assuming the computer 14 has a hub driver, the peripheral device 12 can simulate a
hub by first identifying itself to the PC computer 14 as a hub and subsequently drawing
power from the computer 14.
[0026] Figure 2 shows a second embodiment of the present invention in which two daisy-linked
peripheral devices 12 and 13, such as a PDA connected to a printer, respectively,
can draw power and/or be charged by a computer 14. The first connector 16 connects
the peripheral device 12 to the computer 14, while the second connector 17 connects
the two peripheral devices to each other.
[0027] The software module 18 in the peripheral device 12 enables the peripheral devices
12 and 13 to be charged or powered by the computer 14. The software module includes
a first signal module 20 for sending a first signal to the computer 14 that identifies
the peripheral device 12 as a hub. The second signal module 22 sends a second signal
to the computer 14 that indicates that one more peripheral device is connected to
the peripheral device identified as a hub than is actually connected to the peripheral
device identified as a hub. In this case, the second signal module indicates to the
computer that two peripheral devices are connected to the hub. In fact, only one peripheral
device, namely peripheral device 13 (e.g., a printer), is connected to peripheral
device 12. The computer 14 correspondingly sends enough power (or charge) to supply
two peripheral devices. Some of this power is used by the peripheral device 12 identified
as a hub, and some of the power is used by the other peripheral device 13. It should
be understood that one, two or more peripheral devices can be linked to a computer
and can draw power therefrom in an analogous manner.
[0028] In an embodiment where only one peripheral device is connected to the computer 14,
the peripheral device 12 is connected to the computer 14 with the connector 16, which
can include a cable having a USB compliant plug and port combination. In operation,
the first signal module 20 of the software module 20 sends a first signal to the computer
14 via the connector 16 identifying the peripheral device 12 as a hub. Next, the second
signal module 22 sends a signal to the computer 14 indicating that one peripheral
device is connected to the hub, which is one more than is actually connected to the
peripheral device 12. Typically, the first signal is sent to the computer 14 in response
to an electronic query by the computer 14 that asks the peripheral device 12 to identify
itself. Likewise, the second signal is sent to the computer 14 in response to a query
by the computer 14 that asks how many peripheral devices are connected to the hub.
Answering that one more peripheral device is connected to the peripheral device identified
as the hub (i.e., the peripheral device 12 connected to the computer 14) than is actually
connected to this peripheral device ensures that the computer 14 supplies the appropriate
amount of power to the peripheral device 12. The first and second signals and the
hub driver are all preferably USB compliant, with the hub driver suitable for a Windows
™ setting.
[0029] Figure 3 shows a flowchart for charging or powering a peripheral device, according
to the principles of the present invention. In step 50, software is installed in the
peripheral device 12 that enables the peripheral device 12 to be charged or powered
by a computer 14. In particular, the software module 18, containing the first and
second signal modules 20 and 22, is installed in the peripheral device 12 for this
purpose.
[0030] In step 52, the peripheral device 12 is connected to the computer 14 with a cable
having a USB compliant plug and port combination. In step 54, in response to a query
from the computer 14, the first signal module 20 sends a first signal to the computer
that identifies the peripheral device 12 as a hub despite the fact that in typical
cases envisioned, the peripheral device is not a hub. It should be understood that
this statement does not preclude the peripheral device from providing hub-like functionality
as a secondary role. For example, the peripheral device 12 can be a PDA, a device
whose principal function is not that of a hub's. Nevertheless, a PDA connected to
and drawing power from a computer 14 can be connected to another device, for example
a printer, which also draws power from the computer 14 via the PDA, as shown in Figure
2.
[0031] In step 56, the second signal module 22 sends a second signal to the computer 14
that indicates that one more peripheral device is connected to the peripheral device
identified as a hub than is actually connected to this peripheral device. In the simplest
embodiment, the peripheral device 12 is connected to the computer 14, but not to any
peripheral devices. In this embodiment, the computer 14, acting as though it is connected
to a hub with a peripheral device connected thereto, sends power and/or charge in
step 58 to the peripheral device 12 appropriate for one device.
[0032] In step 58, the computer 14 powers and/or charges the peripheral device 12 in response
to the two signals sent by the software module 18 to the computer 14.
[0033] It should be understood that various modifications could be made to the embodiments
described and illustrated herein, without departing from the present invention, the
scope of which is defined in the appended claims. For example, although emphasis has
been placed on PDA's, other peripheral devices can benefit from the principles of
the present invention.
1. A method for at least one of charging and powering a peripheral device, the method
comprising
installing software in the peripheral device that enables the peripheral device to
be at least one of charged and powered by a computer;
connecting the peripheral device to the computer;
using the software to send a first signal to the computer that identifies the peripheral
device as a hub;
using the software to send a second signal to the computer that indicates that one
more peripheral device is connected to the peripheral device identified as a hub than
is actually connected to the peripheral device identified as a hub; and
the peripheral device identified as a hub receiving the at least one of power and
charge from the computer.
2. The method of claim 1, wherein the peripheral device identified as a hub is one of
a personal digital assistant (PDA), a telephone, a digital camera, a modem, a keyboard,
a mouse, a joystick, a CD-ROM drive, a tape drive, a floppy drive, a digital scanner,
a printer, a data glove and a digitizer.
3. The method according to one of the claims 1 to 2, wherein the step of connecting includes
attaching a cable having a universal serial bus (USB) compliant plug and port combination
from the peripheral device to the computer.
4. The method according to one of the claims 1 to 3, wherein the computer includes a
hub driver that complies with the USB standard.
5. The method of claim 4, wherein the hub driver is a Windows™ based hub driver.
6. The method according to one of the claims 1 to 5, wherein the step of using the software
to send a first signal includes identifying the peripheral device to the computer
as a zero-port hub.
7. The method according to one of the claims 1 to 5, wherein the step of using the software
to send a first signal includes identifying the peripheral device to the computer
as a one-port hub.
8. The method according to one of the claims 1 to 7, wherein the first and second signals
are compliant with a universal serial bus (USB) standard.
9. A system for at least one of charging and powering a peripheral device, the system
comprising
a connector for connecting the device to the computer;
a software module in the peripheral device that enables the peripheral device to be
at least one of charged and powered by a computer, the software module including
a first signal module for sending a first signal to the computer that identifies the
peripheral device as a hub;
a second signal module for sending a second signal to the computer that indicates
that one more peripheral device is connected to the peripheral device identified as
a hub than is actually connected to the peripheral device identified as a hub; and
a power-charge receptor for the at least one of powering and charging the peripheral
device identified as a hub from the computer.
10. The system of claim 9, wherein the peripheral device is one of a personal digital
assistant (PDA), a telephone, a digital camera, a modem, a keyboard, a mouse, a joystick,
a CD-ROM drive, a tape drive, a floppy drive, a digital scanner, a printer, a data
glove and a digitizer.
11. The system according to one of the claims 9 to 10, wherein the connector includes
a cable having a universal serial bus (USB) compliant plug and port combination.
12. The system according to one of the claims 9 to 11, wherein the computer includes a
hub driver that complies with the USB standard.
13. The system of claim 12, wherein the hub driver is a Windows™ based hub driver.
14. The system according to one of the claims 9 to 13, wherein the first signal module
identifies the peripheral device to the computer as a zero-port hub.
15. The system to one of the claims 9 to 13, wherein the first signal modules identifies
the peripheral device to the computer as a one-port hub.
16. The system to one of the claims 9 to 15, wherein the first and second signals are
compliant with a universal serial bus (USB) standard.